condition mean min max ZT0-3 6.882896725749999 6.6854401139999995 7.0803533375 ZT4-7 5.588505287249999 5.2634811804999995 5.913529393999999 ZT8-11 6.7161304484999995 6.0847236334999995 7.3475372635 ZT12-15 5.772511194749999 5.620596915999999 5.9244254734999995 ZT16-19 6.79293750075 6.079489441 7.5063855605 ZT20-23 9.066822358749999 8.5292870445 9.604357672999999